1. Technical Field
The present invention relates to a conductive ink composition for inkjet printing, more particularly to a conductive ink composition for inkjet printing, which has a high concentration of metal, and in which the viscosity is adjusted for improved flow and ejection properties of the ink.
2. Description of the Related Art
Along with recent advances in industrial technology, the rapid development of the IT industry, including the field of mobile communications, is creating a demand for electronic products and data communication devices that are smaller and lighter for convenient portability, and yet are equipped with more functionalities. In accordance with these trends, together with the ongoing efforts to develop various components that are smaller, lighter, more integrated, and have more improved functions, there are also endless demands, such as in the RoHS directive of Europe, for the development of clean production technology, which does not generate toxic materials. In response to these demands, there are developments in various fields of technology, among which is the inkjet printing technology.
The ink for inkjet printing in conventional techniques was mostly of a composition for pigment ink used in regular photograph printing. Since, in the case of pigment ink, the weight of the solid particles is of a lower percentage compared to the weight of the entire ink, the majority of ink preparing techniques concentrate on ejection and color characteristics, rather than on considerations regarding property changes due to high viscosity. However, in the case of conductive ink for inkjet printing, an ink of a high viscosity that has a metal content above a certain value is required in order to provide a thickness that enables its use as metal wiring. However, with higher values of metal content, the viscosity of the conductive ink is raised excessively above a particular level, to render inkjet ejection impossible. Thus, for improved resolution and printing quality in inkjet printing, there is a demand for the development of an ink which allows high-concentration ejection, by adjusting the surface tension and viscosity of the ink.